Tied at one with one out in the bottom of the ninth, Hideki Matsui blasted a 2-2 pitch from Jim Johnson deep into the right field stands for his second career walk-off home run and his 15th home run of the season.
Andy Pettitte gave the Yankees 7 1/3 innings, allowing just one earned run on six hits. The veteran left-hander didn't factor in the decision, but he did strike out eight Orioles in his solid outing.
Orioles starter David Hernandez pitched six innings, holding the Yankees to one run on three hits, but his pitch count rose quickly in the first two innings and ultimately hurt his chances to stay in the game.
The Orioles failed to capitalize on scoring chances in the eighth and ninth innings to put the game away, but it was a pair of stellar defensive plays in the eighth that kept them from taking the lead.
With one out in the eighth, the Orioles had runners on first and third against Pettitte and the dangerous Nick Markakis stepping up to the plate.
Joe Girardi called upon left-handed reliever Phil Coke, who was able to get the job done in an unconventional manner.
Markakis grounded the first pitch to Mark Teixeira at first, and Teixeira fired home in time to get Cesar Izturis, preventing the go-ahead run from scoring.
Then, on the very next pitch, Coke threw a ball that bounced off Molina's chest protector and away from the plate. But Molina recovered to throw the ball to Coke, who was covering home, in time to get Brian Roberts trying to score from third to once again prevent the tying run from scoring.
And after failing to get the big hit with runners in scoring position, the stage was set for Matsui's monstrous homer.
